﻿/*
 * 使用数组区间的函数,本程序基于7.6做出修改,使用两个指针来指定区间.
 *
*/
#include<iostream>
const int ArSize = 8;
int sum_arr(const int * begin,const int *end);
int main()
{
    using namespace std;
    int cookies[ArSize]={1,2,4,8,16,32,64,128};

    int sum = sum_arr(cookies,cookies+ArSize);
    cout << "Total cookies eaten: "<<sum << endl;
    sum=sum_arr(cookies,cookies+3);
    cout << "First three eaters ate "<<sum <<" cookies.\n";
    sum=sum_arr(cookies+4,cookies+8);
    cout << "Last four eaters ate "<<sum <<" cookies.\n";
    return 0;
}

int sum_arr(const int *begin,const int *end)//指向所需的地址的前后
{
    const int *pt;
    int total = 0;
    for(pt = begin;pt!=end;pt++)//将pt设置为指向要处理的第一个元素的指针,循环中不断指针递增,知道pt指向end
        total = total+*pt;
    return total;
}
